Ment to mention they run from 25micron to I think 220micron in that set , but I believe they have 8 bag sets aswell besides the 5 bags.
Really just depends on the method ur trying to go tho.
I actually use something like these if u can, here's a link from Amazon.
iPower Bubble Bag 5-Gallon 5-Bag Herbal Hash Filter Ice Essence Extraction Kit with Free Storage Pouch & 25 Micron Pressing Screen, 5 Colors Kit https://a.co/d/cIlVxXy
HOW (that's important to your question) are you making the hash? Are you using a rosin press? If so it is a range. What you choose is up to you. Larger pore size can give higher yield but you get more solid plant matter & waxes. A smaller pore size can reduce yield but provide a "cleaner" product by filtering out more of the particles.